Sweet Potato Shepherd's Pie

Ingredients

• 2 lbs (900g) sweet potatoes, peeled and cubed
• 4 tbsp (57g) unsalted butter
• 1/4 cup (60ml) milk or cream (full fat is best!)
• 1/4 tsp ground nutmeg
• Salt and freshly ground black pepper to taste
• 1 tbsp (15ml) olive oil
• 1 large yellow onion, chopped
• 2 carrots, peeled and diced
• 2 celery stalks, diced
• 1 lb (450g) ground beef (15-20% fat is ideal for flavor)
• 2 cloves garlic, minced
• 1 tsp dried thyme
• 1/2 tsp dried rosemary
• 1/4 cup (30g) all-purpose flour
• 1 cup (240ml) beef broth
• 1/2 cup (120ml) frozen peas
• 1/2 cup (120ml) frozen corn
• 2 tbsp tomato paste
• 1 tbsp Worcestershire sauce